Different horizons of the application of Weibull distribution for Wind resource assessment: a case study for the Brazilian Northeast region

Abstract

This paper aims to apply the Weibull distribution in the annual and semiannual horizons to contribute to the assessment of wind energy potential in three cities located in Northeastern Brazil (BRNER) region. The potential for wind power in a period can be evaluated by a probability density function such as the Weibull distribution. Different methods for calculating these parameters, including the method of equivalent energy, developed to optimize the application of this frequency distribution to the data collected in northeastern Brazil, were tested. This research seeks to optimize the fit to the data of wind speed and contribute to the reduction of errors in the analysis of wind potential of cities located in the Brazilian Northeast. According to the analysis, it was found that the reduction of the horizon of application provides better efficiency in the adjustment of calculated and observed frequencies. It was also observed that the Weibull distribution applies satisfactorily to the data collected in coastal cities and its efficiency is reduced when applied to distant cities on the coast. Among all analyzed methods for calculating the parameters (k and c) of Weibull distribution, the method of equivalent energy was the one which performed better.